IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group


BackEmblyna acoreensis Wunderlich, 1992

Emblyna acoreensis Wunderlich, 1992

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Arachnida
  • Order: Araneae
  • Family: Clubionidae
NT Near Treatened
IUCN Red List Status:

Countries of Occurrence:
Portugal - Azores


Russell, N.

Lamelas-López, L.

Facilitators / Compilers/s:

Assessment Rationale:

Emblyna acoreensis is a spider species mostly restricted to the lower elevations of the western (Corvo and Flores) and central islands of the Azorean archipelago (Faial, Pico, S. Jorge, Graciosa and Terceira) (Borges et al. 2010). It has a relatively small Area of Occupancy (AOO = 296-1,384 km²) and a globally small Extent of Occurrence (EOO = ca 20,261-21,611 km²), but it is found at >20 locations. It is relatively abundant in Azorean endemic Ericaceae shrubs and in low elevation orchards, and occurs in three Natural Forest Reserves. Based on Ferreira et al. (2016) the habitat will decline as a consequence of climate change (increasing number of droughts, and habitat shifting and alteration). Ongoing, current threats are thought to be leading to declines, and the species is assessed as Near Threatened (NT). 

Geographic Range:

Emblyna acoreensis is restricted mostly to lower elevations, present in the western (Corvo and Flores) and central islands of the Azorean archipelago (Faial, Pico, S. Jorge, Graciosa and Terceira) (Azores, Portugal) (Borges et al. 2010). Within these seven islands, it is known from only three Natural Forest Reserves: Cabeço do Fogo (Natural Park of Faial); Mistério da Prainha, and Caiado (Natural Park of Pico). The Extent of Occurrence (EOO) is 20,261-21,611 km2 and the estimated Area of Occupancy (AOO) is 296-1,384 km2 . 

Portugal - Azores
Extent of Occurrence (EOO):
20,261-21,611 (km2)
Area of Occupancy (AOO):
296-1,384 (km2)
Elevation Lower Limit:
Elevation Upper Limit:
Biogeographic Realms:
Endemic Azores


This can be considered a relatively abundant endemic Azorean spider species, but mostly abundant at low elevation exotic forest, and rarer in orchards. A good adaptation to the human-made habitats is assumed, but current and future decreasing population densities due to pesticide pollution and continuing land-use changes at lower elevations as a consequence of using Pittosporum undulaum forest patches for making wood pellets for fuel, and the creation of cornfields for dairy cattle feeding. Current Population Trend: Decreasing. 

Habitat and Ecology

The species occurs mainly in low elevations in exotic forests and orchards, but is also found in the native forests of three islands at mid altitude (Faial, Pico and Terceira), mostly associated with the canopies of Erica azorica and Morella faya. It is active during the day and night, and builds a messy-looking web with zig-zag lines. The spider is frequently found in the same samples as another Dictyinidae, such as the species Nigma puella and the Clubionid spider Clubiona decora. Systems: Terrestrial.

Major Threat(s):

In the past, the species has probably strongly declined due to changes in habitat size and quality (Triantis et al. 2010). However, the species seems to have survived in a few native forests of Terceira, Pico and Faial, as well as in low elevation human-modified habitats (orchards). The main current threats are the dynamics of the land-use change at low elevations in the Azores, particularly residential and commercial development, for housing and tourism development, as well as agricultural activity. Also important is the impact of pesticides in orchards. Based on Ferreira et al. (2016), the habitat will further decline as a consequence of climate change (increasing number of droughts, and habitat shifting and alteration).

Conservation Actions

The species is not protected by regional law, but its habitat is in some regionally protected areas (Natural Parks of Faial, Pico and Terceira). Degraded habitats should be restored and a strategy needs to be developed to address the current threats from touristic activities and pesticides, and the future threat from climate change. Formal education and awareness are needed to decrease the use of pesticides; while further research is needed into its ecology and life history in order to find the impacts of current and future impacts of agriculture activities and obtain adequate information on population size, distribution and trends. It is also necessary to develop a monitoring plan for the wider invertebrate community in its habitat in order to contribute to a potential future species recovery plan. Monitoring every ten years using the BALA protocol will inform about habitat quality (see e.g. Gaspar et al. 2011).